RU2641989C2 - Spring device and method of producing spring device - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: group of inventions relates to machine building. Device comprises spring (3) with coating (7). Spring support (4) is made of plastic. Spring (3) and its support (4) are glued together with adhesive layer (8). Hardness of adhesive layer (8) is less than the hardness of coating (7). Method includes the steps of manufacturing spring device (2).

EFFECT: improved resistance to wear and improved service life is achieved.

16 cl, 5 dwg

Description

The invention relates to a spring device with a spring, in particular for a car chassis. Such spring devices typically comprise a spring support in which one end of its coil is placed.

A support device for a spring is known from DE 102011002065 A1. The support device comprises an annular liner of flexible spring elastomer in which a part of the coil of the spring is placed. In this case, glue is placed between the spring and the liner, so that the connection of the liner with the spring has an adhesive connection. The adhesive cures at room temperature.

From EP 1165331 B1, a device with a coil spring and a thrust bearing for suspension struts is known. Suspension struts for cars include a shock absorber, which is connected with the upper end to the body, and the lower end - with a knuckle, as well as a coil spring. The lower end of the coil spring through the seat is connected to the shock absorber. The uppermost end coil of the coil spring rests on the thrust bearing.

The connection between the spring and its support is of great importance for safety. When operating the vehicle, particles, such as small pebbles, may get stuck between the end turn of the axial spring and its base. Due to the relative movement between these parts, damage to the spring-protective varnish can occur, which can lead to corrosion of the spring.

The basis of the invention is the task of creating a spring device with a spring and its support, in particular for a car chassis, which would have good resistance to wear and, therefore, a long service life.

This problem is solved by means of a spring device including a coated spring, a spring support made of plastic, and an adhesive layer by which the spring and its support are glued together, and the hardness of the adhesive layer is less than the hardness of the coating.

The advantage is that a relatively soft adhesive layer in the case of load can perceive part of the energy introduced into the device with elastic deformation. An optimal tensile gradient is achieved, since the adhesive forms a flexible layer between the spring coating and its elastic support. In particular, the load in the boundary layer between the spring support and the adhesive is reduced. Thus, relatively small deformations occur in this connecting zone between the adhesive layer and the spring support, so that the wear caused by the load is especially small. In addition, an adhesive layer that is softer than the spring coating prevents damage to the spring coating at high loads.

By hardness of the adhesive layer is meant, in particular, the measured hardness of the adhesive layer in the cured state of the adhesive. For measuring hardness, for example, an indentation method can be used. With this method, an indented body of a certain geometry, also called an indenter, is pressed into the material under study, the indenter material being substantially harder than the sample itself. Regardless of the indenter geometry, a force is assigned to each indentation depth. The quotient of the division of both quantities is a measure of the hardness or stiffness of the sample. Known indentation methods for plastics are, for example, the Shore A method and the Shore D. method. The hardness of metals can be determined, for example, by Vickers or Brinell. In this case, due to the intensifier, plastic deformations are created, which are measured by light microscopy and by which the hardness is determined using the contact area, the corresponding force and the depth of indentation.

Advantageously, the hardness of the adhesive layer is a maximum of 70 Shore D units. Alternatively or additionally, the hardness of the adhesive layer can be intermediate between 40 and 70 Shore D units, and hardness values outside this range are also possible for special applications. In any case, the material of the adhesive layer is such that the hardness of the adhesive layer is less than the hardness of the coating material of the spring. The spring coating preferably has a hardness of at least 70 Shore D.

Further, according to one preferred embodiment, it is provided that the adhesive layer has a greater hardness than the spring support. Advantageously, the hardness of the spring support is at least 50 Shore A. Alternatively or additionally, the spring support can have a maximum hardness of 80 Shore A, and any intermediate value is possible, if also higher than 80 Shore A. Support the spring mainly consists of an elastic material, in particular an elastomer or plastic containing an elastomer, for example rubber, moreover, in principle, thermoplastics or thermosets can also be used as the material of the spring support.

It is preferable that the hardness of the materials used, starting from a spring, consisting mainly of hardened spring steel, to an elastic supporting body through the intermediate layers, gradually decreases. Due to this, the energy introduced into the spring can also be absorbed stepwise, and the elastic adhesive layer due to deformation can absorb part of the energy. In general, due to this, an optimal tensile gradient arises between these parts. In particular, the spring may have a higher hardness than its coating, and / or the coating of the spring may have a higher hardness than the adhesive layer, and / or the adhesive layer may have a higher hardness than the spring support.

Accordingly, according to one embodiment, it can be provided that the spring stiffness is also reduced through its coating and further through the adhesive layer to the spring support. In particular, the spring may have a higher stiffness than its coating, and / or the coating of the spring may have a higher stiffness than the adhesive layer, and / or the adhesive layer may have a higher stiffness than the spring support.

On the contrary, the spring elasticity through its coating and further through the adhesive layer to the spring support can increase. In particular, the spring support may have a higher elasticity than the adhesive layer, and / or the adhesive layer may have a higher elasticity than the spring coating, and / or the spring coating may have a higher elasticity than the spring.

Accordingly, the tensile elongation from the spring through its coating and further through the adhesive layer to the spring support can also increase. Tensile elongation characterizes the deformation ability or ductility of the material. Tensile elongation describes the residual change in length after rupture related to the initial measured length of the specimen in a tensile test. In particular, the spring support may have a higher tensile elongation than the adhesive layer, and / or the adhesive layer may have a higher tensile elongation than the spring coating, and / or the spring coating may have a higher tensile elongation than the spring. The adhesive layer has a predominantly tensile elongation of at least 5%, in particular at least 50%, particularly preferably at least 100%. The upper limit of the elongation of the adhesive layer can be, for example, a maximum of 300%.

According to one embodiment, the adhesive layer may have a thickness of at least 0.1 mm, in particular at least 0.5 mm. Alternatively or additionally, the adhesive layer may have a thickness of a maximum of 3.0 mm, preferably a maximum of 1.5 mm, in particular a maximum of 1.0 mm. It is especially optimal for reliable connection of the spring and its support with good damping properties, if the adhesive layer has a thickness of 0.5-0.7 mm. However, it is understood that any other thickness value between 0.1 and 3.0 mm is also possible. As the material of the adhesive layer, for example, a chemically set adhesive based on an acrylic derivative can be used.

To achieve a certain thickness of the adhesive layer, spacers can be provided by which the coating surface and the surface of the spring support can be maintained at a distance from each other, and the space formed between the coating surface and the surface of the spring support is at least substantially filled with the adhesive layer . By the expression “at least to a very large extent” it should be understood, in particular, the possibility that the gap formed between the spring support and the spring and filled with an adhesive layer can also have technologically determined cavities or air inclusions. Advantageously, the gap is for the most part, in particular at least 90% filled with an adhesive layer.

According to one preferred embodiment, the spacers can be arranged so that the spring and its support are oriented relative to each other in the axial direction and / or in the radial direction, respectively, relative to the axis of the spring. In particular, several spacers can be located in the direction of the periphery along the coil of the spring. Alternatively or additionally, several spacers, when viewed in cross-section through a spring wire, can be positioned offset relative to each other along a portion of the periphery of the spring wire. In General, this can achieve the orientation of the spring in the radial and axial directions relative to the supporting body.

The spacers can be made, in particular, in the form of elastic bodies having a certain elastic compliance. Thus, the support can be used for springs of different wire diameters. In the case of a spring wire of smaller diameter between the spacers and the spring, a fit can be formed with a gap or with a slight interference fit, and the spacers keep the spring at a distance from the surface of the supporting body. When using a spring wire of a larger diameter between the spacers and the spring, an interference fit can be formed, and also in this case, the surface of the spring is held by the spacers at a distance from the surface of the supporting body.

According to one possible embodiment, the spacers can be made in the form of protrusions spaced from the surface of the spring support. Mostly, the protrusions are made in one piece with the support body or molded on it. For good abutment and insertion, it is favorable if at least three spacers, in particular at least six spacers, are distributed in a cylindrical section through the spring support along the periphery of the spring support. Alternatively, or additionally in radial section through the spring support, at least three, in particular at least four spacers can be distributed along the groove to accommodate the spring.

The spring support is made in such a way that the spring, if viewed in radial section through its support or in cross section through the spring wire, is placed in its support with a range of entanglement angle of at least 30 °, mainly 100 ° and / or maximum 150 ° , and by means of the adhesive layer is connected to the support. Due to this, the loads acting between the spring and its support are distributed as evenly as possible, and good bearing is achieved. In particular, it is envisaged that the adhesive layer in the above-mentioned range of the angle of the coil around the spring wire and / or in the range of the angle of the coil along the coil of the spring around the axis of the spring has a substantially constant thickness. By constant, mainly by thickness, it is necessary to understand certain technological tolerances of the thickness of the adhesive layer ± 10%.

The spring can be made in the form of a helical spring having a helically twisted wire. In this case, one end section of the coil spring, which can pass in axial form, for example, 180-360 ° around the axis of the spring, is placed in the spring support. Moreover, the contour of the spring support is predominantly consistent with the cross-sectional shape of the spring, so that they are reliably interconnected. This applies mainly to any type of spring used, i.e. also to other springs than to coil springs. A coil spring can be made, for example, cylindrical or conical. The center line of the coil spring, which can be defined as the sum of all the centers of the envelope, can be curved in one or more dimensions, for example C- and / or S-shaped. Further, the coil spring may have a varying wire diameter, a variable pitch and / or a diameter varying in length. It is understood that the spring device may, in principle, also comprise any other spring. In particular, the spring device may comprise any coated spring for which an adhesive layer of elastic material located between it and its elastic support allows one to expect technical advantages. For example, the spring of the spring device can also be made in the form of a leaf, wavy or plate spring.

The solution further consists in a method of manufacturing a spring device with a spring and its support, which may have one or more of the above-mentioned embodiments, which includes the following steps: manufacturing a spring support from an elastomer-containing plastic of the first hardness, manufacturing an adhesive of the second hardness that is greater than the first hardness spring supports, manufacturing a spring with a coating of third hardness that is greater than the second hardness of the glue, applying glue to the spring support and putting the spring on the support provided with glue in this way ohm, that the surface of the coating and the spring seat surface are kept at a distance from each other.

Thanks to the method, the same advantages are achieved as due to the device described above, so that in this regard, in order to avoid repetitions, reference is made to the description. It is clear that all the features of the product are related in meaning to the method and that, on the contrary, all the features of the method are related in meaning to the product.

To support the spring, in particular, plastic containing an elastomer with a hardness of at least 50 Shore A and / or a maximum of 80 Shore A is used. Alternatively or additionally, adhesive with a hardness of at least at least 40 Shore is used D and / or a maximum of 70 Shore D units. Alternatively or additionally, the coating may have a hardness of at least 70 Shore D units.

According to one preferred embodiment of the method, after applying glue to the spring support, the latter is held, essentially without compression, relative to its support. By the expression “without compression” it should be understood, in particular, that the spring due to its own mass and, in the case of its own mass, the orienting element, with which the spring is oriented relative to its support during the curing of the adhesive, is pressed against the support. Curing of the adhesive occurs, in particular, at room temperature.

The proposed spring device with a coil spring as a spring can be used, in particular, for the chassis of the car. For this application, coil springs are also called axial springs or chassis springs. In this case, the spring support, which can also be called the base of the spring, rests on the spring plate of the chassis or body.

A preferred embodiment of the invention is explained below with reference to the drawings, in which the following is presented:

- FIG. 1: the proposed spring device with a spring and its support in perspective form;

- FIG. 2: radial section of the spring device of FIG. 1 through a plane between two adjacent struts of the spring support;

- FIG. 3: detail of the spring support of the spring device of FIG. 1 in three dimensions;

- FIG. 4: radial section of the spring support of FIG. 1 through a plane with spacers;

- FIG. 5: a schematic radial section of a spring support for the proposed spring device.

FIG. 1-5 below are described together. The proposed spring device 2 is shown, comprising a spring 3 and its support 4, to which an end portion 5 of the spring 3 is connected. The spring 3 consists of a suitable spring material, in particular of hardened spring steel, and, in principle, other spring materials are also possible, such like fiber reinforced plastic. The spring support 4 consists of an elastic material, in particular plastic or rubber containing an elastomer.

The spring 3 is made in the form of a coil spring containing a wire wound around the center line of the spring. At its opposite end to the first end portion 5, the coil spring 3 has a second end portion 6, which can be placed in a second spring support (not shown). The spring device 2 can be used, in particular, in the chassis of the car, and in this case, the spring device in cooperation with the shock absorber dampens or dampens the vertical movements of the car.

The spring 3 is provided with a coating 7, which should protect it from stone blows and corrosion. Coating 7 can be applied to the spring by powder spraying. For this, according to one possible embodiment, a single coating can be used, the spring being first subjected to zinc phosphating and then powder coating. For particularly high requirements, a double coating can also be used, with a thin base layer (Base-Coat) applied to the zinc phosphate layer and then a thicker energy-absorbing outer layer (Top-Coat). It is understood that other coatings of other suitable materials are possible.

The coated spring 3 (coating 7) is glued by means of an adhesive layer 8 with a support 4. The adhesive layer 8 has a lower hardness than the coating 7. In particular, it is provided that the spring coating has a hardness of at least 70 Shore D. In accordance with this, the hardness of the adhesive layer 8 is a maximum of 70 Shore D. In order for the adhesive layer 8 to have sufficient strength and not to form any undesirable weaknesses in the device, the lower limit of hardness of the adhesive layer 8 should not be lower than mainly 40 Shore D. B quality for the material of the adhesive layer, for example, a chemically set adhesive based on an acrylic derivative, in particular methyl methacrylate, can be used.

It is further provided that the adhesive layer 8 has a greater hardness than the support 4, and for the latter, an upper limit of predominantly 80 Shore A must be observed. To ensure sufficient strength of the support 4, it is favorable if it has a hardness of at least 50 Shore BUT.

Due to this embodiment, the hardness of the materials used, starting from the spring 3 through its coating 7, the adhesive layer 8 to the elastic supporting body 4 through the intermediate layers is gradually reduced. Due to this, the energy introduced into the spring 3 can also be absorbed stepwise, and the elastic adhesive layer 8 due to the elastic deformation can absorb part of the energy. Alternatively or additionally, it can also be provided that the stiffness of the spring 3 decreases through its coating 7 and further through the adhesive layer 8 to the support 4.

On the contrary, the elasticity of the material used can increase from the spring 3 through its coating 7 to the support 4. Alternatively or additionally, it can also be provided that the tensile elongation increases from the spring 3 through its coating 7 and further through the adhesive layer 8 to the support 4. Explosive elongation is a measure of the deformation ability or ductility of a material. In particular, the material of the adhesive layer is such that in a cured state it has a tensile elongation of at least 5%, in particular at least 50%, preferably at least 100%.

As follows, in particular, from FIG. 2, the adhesive layer 8 has a greater thickness than the coating 7. Moreover, the thickness of the adhesive layer 8 can be, for example, 0.5-0.7 mm, and smaller or larger thicknesses of the adhesive layer are also used. In particular, when applying a double spring coating (Dual-Coat), the thickness of the spring coating 7, which can be 0.5 mm or more, can also be larger than the adhesive layer 8.

The spring support 4 is made annular or in the form of an annular segment and has a longitudinal axis, which in the mounted state is at least close to the axis of the spring. The support 4 has a groove 10, which extends in the direction of the periphery around the longitudinal axis of the support 4 and in which the twisted end section 6 of the spring 3 is placed. Moreover, the shape of the groove 10, in particular also its axial rise along the length of the periphery, corresponds to the shape of the spring 3 or the end coil. A stop 11 is formed at the end of the groove 10, on which the end end 12 of the spring 3 rests in the direction of the periphery.

In order to ensure the maximum uniform thickness of the adhesive layer 8 in the entire connection zone between the coated spring 3 and its support 4, the support 4 has several spacers 9. They are distributed in such a way that the spring 3 is oriented relative to the support 4 in axial and radial directions, the indications being “axial "And" radial "refer respectively to the axis of the spring and the axis of the support. For this, as follows, in particular, from FIG. 3, several spacers are provided along the circumference of the periphery and along the radial extent of the groove 10 in which the end portion 6 of the spring 3 is located.

Due to the struts 9, the surface 13 of the coating 7 and the surface 14 of the support 4 are kept at a distance from each other, and the gap formed between the surface 13 of the coating 7 and the surface 14 of the support 4 is filled with an adhesive layer 8. Thus, the spring 3 and the support 4 are firmly glued to each other forming a structural unit. Spacers 9, as follows, in particular, from FIG. 3, made in the form of spikes, which are made in one piece with the supporting body 4 and are separated from the surface 14 of the groove. The spacers 9 are distributed along the periphery in several rows of 15, 15 ', 15' ', etc. As follows from FIG. 4, in a radial section through the supporting body 4, several rows of 15 spacers 9 are provided. It is clear that a different number can also be used than in this case seven rows of spikes, or that the spacers 9 can also be distributed unevenly on the surface 14 of the groove. In any case, it is favorable if the spacers are distributed so that the orientation of the spring 3 in the radial and axial directions relative to the supporting body 4 is achieved.

The height of the individual spacers 9 defines at least approximately the thickness of the gap formed between the surface 14 of the groove and the surface 13 of the spring, and thereby also the thickness of the adhesive layer 8. Therefore, the spacers are preferably 0.5-0.7 mm high, and other values are possible. The spacers 9 are made for good removability from the mold mainly in such a way that they taper from the surface 14 of the groove in the direction of its end. In this case, the spacers 9 are made approximately in the shape of a truncated cone, and a spherical shape is also possible. The spacers 9 are made of the elastic material of the support body 4, so that the support 4 can be used for various springs 3 of different diameters of the wire.

As follows, in particular, from FIG. 5, the support 4 is preferably made in such a way that the spring 3, when viewed in a radial section through the support 4 or in cross section through the spring wire, is placed in the support 4 with a winding angle of at least 30 °, preferably at least 100 ° and / or maximum 150 °. Due to this, the loads acting between the spring 3 and the support 4 are distributed as evenly as possible, and good maintenance of the spring forces is achieved.

A method of manufacturing the proposed spring device 2 may include the following steps: manufacturing the spring support 4 from elastomer-containing plastic, making glue, the glue being harder than the spring support, manufacturing the coated spring, the coating being harder than the glue, applying glue to the spring support 4 and putting on the spring 3 onto an adhesive-supported support 4 such that the surface 13 of the coating 7 and the surface 14 of the support 4 are kept at a distance from each other.

After applying glue to the support 4, the spring 3 is put on it and for the time of curing of the glue is fixed or held relative to it. Curing of the adhesive occurs, in particular, at room temperature. The cured adhesive then forms an adhesive layer 8, which firmly connects the spring 3 to its support 4. The adhesive connection, in particular, is such that it can no longer be disconnected without breaking.

The advantage of the spring device 2 is that the adhesive layer 8 can elastically deform and absorb some of the energy introduced into the system due to elastic deformation. The stresses in the boundary layers of the interconnected materials or parts are thus lower, so that the wear caused by the load is also low when the spring device is used.

List of Reference Items

2 - spring device

3 - spring

4 - spring support

5 - end section

6 - end section

7 - coating

8 - adhesive layer

9 - spacer

10 - groove

11 - emphasis

12 - end

13 - surface

14 - surface

15 - row

A - axis

Claims (16)

1. A spring device (2) comprising a spring (3) with a coating (7), a spring support (4) consisting of plastic, and an adhesive layer (8) by which the spring (3) and its support (4) are glued together characterized in that the hardness of the adhesive layer (8) is less than the hardness of the coating (7) of the spring (3). 2. The device according to claim 1, characterized in that the hardness of the adhesive layer (8) is greater than the hardness of the spring support (4). 3. The device according to claim 1 or 2, characterized in that the hardness of the adhesive layer (8) is at least 40 Shore D units and / or a maximum of 70 Shore D units. 4. The device according to p. 1 or 2, characterized in that the adhesive layer (8) has a tensile elongation of at least 5%, in particular at least 50%, mainly at least 100%. 5. The device according to p. 1 or 2, characterized in that the hardness (H) of the coating is at least 70 Shore D. 6. The device according to claim 1 or 2, characterized in that the hardness of the spring support (4) is at least 50 Shore A units and / or a maximum of 80 Shore A units. 7. The device according to claim 1 or 2, characterized in that the adhesive layer (8) has a thickness of at least 0.1 mm and a maximum of 3.0 mm, in particular at least 0.5 mm and a maximum of 1.0 mm . 8. The device according to claim 1 or 2, characterized in that it contains spacers (9), by which the surface (13) of the coating (7) and the surface (14) of the spring support (4) are kept at a distance from each other, the space formed between the surface (13) of the coating (7) and the surface (14) of the spring support (4) is at least very substantially filled with an adhesive layer (8). 9. The device according to p. 8, characterized in that the spacers (9) are distributed so that the spring (3) and its support (4) are oriented with respect to each other in the axial direction and / or in the radial direction relative to the axis (A ) springs. 10. The device according to p. 8, characterized in that the spacers (9) are made in the form of protrusions spaced from the surface (14) of the spring support (4). 11. The device according to p. 8, characterized in that several spacers (9) are displaced relative to each other in the direction of the periphery along the coil of the spring (3) and / or on the part of the periphery of the spring wire. 12. The device according to claim 1 or 2, characterized in that the spring support (4) is made in such a way that the spring (3), if viewed in cross section through the spring wire, is placed in its support (4) with a range of entanglement angle of at least at least 30 °, preferably at least 100 °, and by means of the adhesive layer (8) is connected to the support (4), moreover, the adhesive layer (8) in the range of the angle of entanglement has a substantially constant thickness. 13. A method of manufacturing a spring device with a spring and its support, in particular according to any one of paragraphs. 1-12, in which the following steps are performed: the spring support (4) is made of plastic of the first hardness containing the elastomer, the second hardness adhesive is made, which is greater than the first hardness of the spring support (4), and the spring (3) is coated with a third hardness coating, which is larger the second hardness of the glue, apply glue to the spring support (4) and put the spring (3) on the adhesive provided with the support (4) so that the surface (13) of the coating (7) and the surface (14) of the spring support (4) are kept at a distance apart from each other. 14. The method according to p. 13, characterized in that for the support (4) of the spring, plastic of the first hardness (H) is used, at least 50 Shore A units and a maximum of 80 Shore A units, adhesive of the second hardness, at least 40 Shore D units and / or a maximum of 70 Shore D units and / or a third hardness coating (7) of at least 70 Shore D. 15. The method according to p. 13 or 14, characterized in that the adhesion of the adhesive is carried out mainly without pressure. 16. The method according to p. 13 or 14, characterized in that the adhesion of the adhesive is carried out at room temperature.

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